• DYMAT® Structural Bearings: Sliding Bearings
  • DYMAT® Structural Bearings: Sliding Bearings-1
  • DYMAT® Structural Bearings: Sliding Bearings-2

Sliding Bearings

DYMAT® Structural Bearings

Design 

Type 1 Design

Total dead plus live load on bottom pad maximum of 1000 psi with maximum dead load of 750 psi

Maximum deflection at 2000 psi is approximately 10% of thickness of bottom pad. Design for 2% rotation in l direction

Design coefficient of friction 
A.  750 to 1000 psi of .04
B.  500 to 700 psi of .05

To design top plate overlap of bottom pad:  bottom pads less than 40 sq in / minimum edge is 1/2 in;
bottom pads more than 40 sq in / minimum edge is 3/4 in

Complete bearing assembly capable of test to 5000 psi for 5 minutes with no visible damage

Recommended operating temperature range is -40ºF to 180ºF

Neoprene material meets AASHTO specification. The bearings can also be manufactured in natural rubber to AASHTO specification.

 

Type 2 Design

Total dead plus live load on bottom pad maximum of 2000 psi with maximum dead load of 1700 psi

Maximum deflection at 2000 psi is approximately 10% of thickness of bottom pad. Design for 2% rotation in l direction

Design coefficient of friction
A.  1000 to 1500 psi of .04
B.   1500 to 2000 psi of .03

Complete bearing assembly capable of test to 5000 psi for 5 minutes with no visible damage

Recommended operating temperature range is -70ºF to 200ºF

Special polyurethane meets DYMAT™ material specification, which is available on request.

All other details and installation same as Type 1 bearings.

Materials 

Type 1​
 

​Top Plate​
ASTM A36 or G40.21 steel plate 1/2 to 1 in thick with a 304 stainless steel highly polished bright annealed lower surface. The stainless steel sheet is continuously welded to the steel plate.

​Bottom Pad
Consists of 60 Durometer Neoprene or natural rubber materials to meet the AASHTO specifications. One or two 1/8 in shims are molded into the pad with a minimum of 1/8 in cover of Neoprene over the edges of the steel shims. 1/32 in thick virgin Teflon® sheet is molded onto the top surface of the pad.

 

Type 2​
 

Top Plate
ASTM A36 or G40.21 steel plate 1/2 to 1 in thick with a 304 stainless steel highly polished bright annealed lower surface. The stainless steel sheet is continuously welded to the steel plate.

Bottom Pad
High quality polyurethane developed specially for application. The Teflon® sheet is bonded to 1/8 in thick fiberglass or steel sheet which is molded into pad. The Teflon® sheet is 1/32 in thick virgin Teflon®.

Top Plate
l = plan dimension in direction of rotation
w = plan dimension
t = thickness excluding stainless steel

Bottom Pad
a = plan dimension in direction of rotation
b = plan dimension
c = thickness including Teflon®

Features

  • Low profiles
  • Simple Installation
  • Completely flexible anchorage design
  • DYMAT® manufactures plates and pads to any size required.
  • Large movement capabilities by sliding on low friction materials
  • Design allows for rotation of beams and upper structure
  • Design isolates the structure from noise and vibration by use of elastomeric pads
  • Long life because of excellent materials and conservative working stress levels

Data Sheets

Type 1 Sliding Bearing 

Type 2 Sliding Bearing

Installation

Type 1 & 2
 
Bearings always installed with steel plate on top of bottom pad

Bearing seat on which bottom pad rests must be true level ± 1/32 in

For precast concrete, carefully shim bearings so they are uniformly
loaded. Also, select a bearing having 25% extra load capacity in order to minimize the effect of lack of uniformity

Where top plates are not cast into concrete beams, a 1/8 in masonry pad should be bonded to top plate.